1. Field of the Invention
The present invention relates to bulk material handling equipment and in particular to apparatuses for discharging material from reaction vessels.
2. Brief Description of the Prior Art
It has been suggested that for certain processes, such as long retention time sulfite wood chip treating, the use of a vertically walled reaction vessel would have advantages over the use of an inverted conical vessel. In view of overhead space limitations, it might also be necessary to carry out such processes in a vertically walled reaction vessel having a relatively large diameter of perhaps 8 feet instead of in a tall, narrow vessel of equivalent capacity.
Reaction vessels are often conventionally discharged by means of screw conveyors, and it is well known that in such an arrangement screw diameter is desirably proportioned to reaction vessel diameter. Thus, one disadvantage to using a large diameter, vertically walled reaction vessel heretofore has been that the wide vessel would require a considerably larger and more expensive conveyor screw to empty it as compared to a tall, narrow vessel of equivalent capacity. For example, an 8 foot diameter vertically walled reaction vessel might conventionally require a screw conveyor discharger which is 42 inches in diameter.